Hey folks... Yet another fuel consumption thread.

Just planning a trip to see my Mum who live on the Isle of Skye.

Would really love to get there on one tank to save fueling on the way (around 450 miles door to door).

So my question is... do you think I could make it?

I usually only drive about 60 on the motorway etc anyway but do you think I would have to reduce my speed further to around 55 to get there on one tank?

I would have to get around 50mpg (based on the 42 litre tank) to achieve this and the best I have done was 43.7 going to germany (that was for the whole trip so included a thrash on the autobahn and town driving keeping with the "spirited" flow of traffic ).

Whats most mileage you have got from one tank of fuel?

Thanks

Phil

erm, thinking about it logically, the engine is most efficient at the rpm where you are getting peak torque because that's where the highest ve is. so it will be at whatever speed that rpm gives you for best fuel economy

About 4250 rpm for me then, thats about 105mph

Back to the drawing board then Tom :P

If you're not sure you can make it on a tank, fill up at "Western Gateway" Esso station on the A82, about 2 miles before Dumbarton, at a Little Thief, just across from a Brewer's Fayre, and actually just off the main road. Extra trip distance about 50 yards. Oh and cheaper than anyplace else I know of that you'll see before Broadford on Skye.

About 4250 rpm for me then, thats about 105mph

Back to the drawing board then Tom :P

Hehe! Don't quite think 4250rpm and 105mph would get you your best MPG figure yet but ya never know Tom could be on to something here!

If you're not sure you can make it on a tank, fill up at "Western Gateway" Esso station on the A82, about 2 miles before Dumbarton, at a Little Thief, just across from a Brewer's Fayre, and actually just off the main road. Extra trip distance about 50 yards. Oh and cheaper than anyplace else I know of that you'll see before Broadford on Skye.

Cheers... will take it steady and see how I go and will bear this one in mind!

Phil

Another thought on this; Dumbarton's quite possibly about where I'd think of stopping if I was planning "proper lunch" on that trip anyway. About a mile on from the place described, and just off the A82 again, there's a proper Hotel, the Abbotsford, visible and signposted; only a £1 or 2 a head more (max, for equivalent dishes) than the LT and BF, and well worth paying the extra for food that's actually cooked on the premises by a real chef.

Or if you're more a bacon roll and mug of tea for lunch type, I can give you directions to somewhere good, and cheap, in the town centre.

Just looked it up.

Its 433 miles door to door.

Dumbarton it 230 miles from home with 200 to go so that would be a perfect place to stop and fuel. Even if I can make it all the way on one tank I think I will still stop there to get fuel and lunch to top the car's and my tank up! hehe

Will be recording my mileage etc properly and will fill up before I set off so I will know exactly what my mileage will be for the trip.

Thanks

Phil

my bet is 5th gear 2800 rpm thats 90 km/h.

after 55mph the air resistance becomes a factor, and the best FE does come in the rpm the engine has the best torque in therms of Thermal dinamic and engine eficiency

so right in the middle of best torque and less air resistance is your figure

from: -> ?koda Auto - Felicia

Fuel Consumption: (90 km/h – 120 km/h – city) 4.3 - 6.1-6.3 litres/100 km (1.9 D) to 5.9 – 7.6 – 8.7 litres/100 km (1.6)

so 90 km/h is 5.9 L/100km that's 700 km | 442 miles on a full tank

I seem to be quite lucky on the mpg at the last 2 fills unless i got the numbers wrong. The most likely contributory factor is probably adding a dose of redex. I guess renewing the gear oil with slightly thinner gear oil may contribute slightly.

last time i went to plymouth in the favorit, the petrol was 19.9p, the red light had just came on when i filled it up and i put in £40 all in i did a few miles over 400 there and back (didnt drive whilest i was there) i was doing about 80 mph all the way there and back and the red light just flicked on about 5 miles from home. whats that work out to roughly?

Last summer, on french motorways, I was driving at 60-65 mph all the way long and did drive 411,5 miles between 2 fuel tank filling! ^^

Here are the official consumption figures:

Fuel consumption according to EHK R84 regulations

Depending on driving style and behavior, vehicle acceleration, braking and driving speed, overall age and operating condition of the car, temperature, weather conditions, traffic, road conditions, drive systems, and powered accessories, these values can vary.

IMPERIAL

METRIC

Edited 18 June, 201214 yr by masster

there is an exceptionally well-written and detailed account by Alastairq in the 'WHY THE FELLY' thread detailing precisely how to achieve 50+mpg from a felly. - best of luck and safe journey!

as much as I like Alastairq's passion for Felicia and his eloquent essays (I get tired even read them let alone write them) he's too much into a minute driving style that could easily ruin my driving pleasure.

I would certainly expect (and appreciate) an essay centered on technical issues to check in order to get higher mpg.

I'm not referring to those generic noob guides beginning with 'lose any unnecessary weight in the trunk'... but engine settings, tweaks, maintenance, better parts SPECIFIC for Felicia.

until some old and wise Felicia owner writes it, I have a question that never had a clear answer.

when do you get better mpg in a cruising scenario and taking the foot off the throttle pedal to decelerate?

when you keep it in GEAR? or when you shift IN NEUTRAL and let the engine idle?

I am more interested in carburetor cars, as I have one.

Edited 19 June, 201214 yr by masster

he's too much into a minute driving style that could easily ruin my driving pleasure.

Depends on whether one has enough surplus income to finance frequent 'driving-for-pleasure'...or whether....as I suspect would be the majority of cases....folks see the Felicia as a cheap means to an end....transport?

But I don't have a 'need' to drive for pleasure. [ignoring the fact that in the online Skoda world, others know I was..and may well yet be, a keen Trials competitor]...since I spend my entire working day messing around at the more enjoyable end of the driving world...being a Specialist Instructor at the place linked below.....and have been doing so for at least a decade and a half ! [how time flies when you're having fun?}

http://en.wikipedia.org/wiki/Defence_School_of_Transport

Within the limitations of traffic and road conditions, and the Law, any more 'enthusiastic' a driving style than mine may well prove to be risky at best.

I aimed to show those on here who may yet have acquired sufficient driving knowledge, that it is easy to achieve economic fuel consumptions with this car.........simply by making full use of the characteristics of modern technologies, without resorting to the old-style driving techniques that prevailed 30 years ago.

when do you get better mpg in a cruising scenario and taking the foot off the throttle pedal to decelerate?

when you keep it in GEAR? or when you shift IN NEUTRAL and let the engine idle?

I have already suggested answers to those questions.

In a Felicia Mpi [as distinct from a carburettor 136 engine...which may be your experience?]..when going onto 'over-run' [foot-off gas pedal]...especially from 'speed'... effectively , all fuel is returned to the fuel tank.

Hence as an example, on a 2 mile stretch of road, cruising at 60...if one is 'on the gas' for one mile, and 'off the gas' for one mile...over the entire distance, one only uses fuel for half that distance.

If the driver stays in top gear for as long as possible then, using momentum the rate of speed reduction is less....therefore a greater distance is covered for little or no fuel usage.

The alternative question quoted...that of free-wheeling [shifting into neutral]...[or 'out-of-cog', to use an old-style driver's term?]....is today not only a false economy, it has it's dangers with a reduction of control over what the car does.

The false sense of economy comes from the fact the engine management system will in fact inject fuel into the engine at tick-over revs [idle speed]...therefore fuel is being used whilst the engine is idling. [136 mpi]

With reference to engines fuelled by carburettor, all the above does not apply, as fuel is constantly being fed into the engine by the carb, hence different driving styles are needed, simply to maximise that fuel usage.[ limiting cruising speeds, different gearchange points, etc.]

Hence, I can achieve consistent consumptions in the Mpi 136 of 47-49mpg's....and barely in the 30's with my carburetted 136 Rapids.....and with very different driving styles needed as well.

With reference to engines fuelled by carburettor, all the above does not apply, as fuel is constantly being fed into the engine by the carb, hence different driving styles are needed, simply to maximise that fuel usage.[ limiting cruising speeds, different gearchange points, etc.]

from my knowledge, type 135 engine consumption at idle is 0.8 liters/hour, but never checked.

by not having an instant consumption gauge, it is very difficult to say when the engine is 'sucking' more fuel: in gear or at idle.

I understand your point about car's dynamic in gear, but just for the theoretical aspect, I am curious to know for instance what happens when going on a 1 mile straight downhill, in gear or at idle.

so, alastairq, please stick around a while on this subject and advice on the following issues:

- can I insert a vacuum operated valve (damper style) BEFORE carburetor needle valve to mimic the MPI over-run stage? the valve would sense the off-pedal status (high vacuum) and close fuel admission to carburetor, all fuel from pump output going back to tank

- I try to make an instant fuel consumption gauge by measuring the fuel flow from pump and the return fuel flow to tank using a differential pressure sensor. another method would be to simply have a vacuum gauge onboard and to try driving having a constant highest vacuum reading. what do you think?

right now, after carefully tinkering my carburetor, I successfully reached the factory specifications (49 mpg at 55 mph) but I am not too happy about city consumption. 32 mpg in city for a 1.3 liter car seems too much.

Edited 1 July, 201214 yr by masster

I don't have the relevant technical details, but have a web search for SU HIF44 carburetor. Some versions of it had a valve that introduced air after the throttle valve to reduce fuel drawn through the jet wehn you'd sufficient revs on a closed throttle.

What you're trying to do with a fuel return just won't work on a carburettor because when you start passing fuel back to the tank, the level in the float chamber falls, causing the float to fall, drawing more fuel from the tank. Even if it had worked from that viewpoint, you'd get a horrible flat spot when you tried to roll the power back on.

What if we try something more radical?

Let's say... the Vortex Air-feed system described at http://www.free-ener...om/Chapt10.html

Please search in that page for "Vortex Air-feed system".

I would definitely give it a try if I had the machining tools available.

There are also many other solutions in that page that might be of interest.

The author of that chapter is a man that I respect very much, his name is Patrick J. Kelly, he is British and he gathers and maintains a very practical collection of energy related devices that will change our life soon.

His e-book can be downloaded from this address: http://www.free-energy-info.co.uk/PJKBook.html

You can contact him easy, he has lots of information directly from those inventors he writes about.

Perhaps we can test on our Felicia cars some of those devices before gasoline will cost more than car itself...

Edited 26 September, 201213 yr by adurer